Power-operating means for rudders



1,577,919 A. MQNAB POWER OPERATING MEANS FOR RUDDERS March 23 1926.

Filed May 9, 1924 3 Sheets-Sheet l March 23 1926.

A'. M NAB POWER OPERATING MEANS FOR RUDDBRS 3 Sheets-Sheet 2 Filed May 91924 March 23 192s. 1,577,919

A. MCNAB POWER OPERATING MEANS FOR RUDDERS Filed May 9,1924 3Sheets-Sheet 5 8' 5, .813 2a" AHEAD \ASTERN nssrr 1 MOTOR. v

Patented Mar. 23, 1926.

UNITED STATES ALEXANDER MGNAB, OF BRIDGEPORT, CONNECTICUT.

POWER-OPERATING MEANS FOR RUDDERS.

Application filed May 9, 1924. Serial No. 712,075.

To all to item it may concern Be it known that I, ALEXANDER MCNAB, asubject of the King of Great Britain, residing at Bridgeport, State ofConnecticut, have invented certain new and useful Improvements inPower-Operating Means for ll-udders', of which the following is aspecification.

This invention relates to the maneuvering gear of ships or boats and hasparticular reference to gear of this lnnd' 1n which the rudder is formedof two substantially curved blades mounted behind the propeller in sucha way that they may be varied from parallelism to a mutually inclinedposition in which substantially no water is allowed to pass between theblades, this form of rudder maneuvering gear is fully described in U. S.Patent No. 1,186,210. p

The form of'maneuvering gear referred to has been found in practice togive very much improved maneuvering qualities to the vessel and to beparticularly valuable in cases where it is undersirable to vary thespeed of the engine as in motor driven vessels, allmaneuvering such; asturning n a narrow compass or reversing being carried out entirely bythe rudder setting. In addition, the quicker stopping of'the vesselwhich can be obtained from the use of the rudder is very greatadvantage. Many further advantages will be obvious to those familiarwith the navigation of ships or Boats.

In view of the advantages obtained by the use of this rudder maneuveringmeans it has been fitted to a very large number of vessels. Hitherto therudder setting has been manually controlled but it has been found inpractice that whereas manual control is entirely satisfactory in smallvessels is desirable to fit power means of control forthe maneuveringgear in the case of larger vessels and this invention specificallyrelates to such powercont-rol means.

It is an object of the invention to provide a power operated controlmeans for maneu vering gear of the kind described which canbe'controlled from a point adjacent the steering wheel. I

It is a further object'of the invention to provide an electrical poweroperating means for maneuvering gear of the kind described.

It is a still further objectof the invention to provide brake mechanismto ensure that the movement of the mechanism is arrested at the desiredinstant.

It is a still further object of the invention to provide automatic meansto limit the movement of the rudder blades.

It is a still further object of the invention to providea power drivenrudder control in which while thenecessary manipulation has been reducedto great simplicity, a thoroughly reliable apparatus is provided capableof all required adjustments. v

It is a st-illfurther object of the invention to soarrange theapparatusas to" form a compact structure mountable in a small space inthe most convenient position as for instance directly over the rudder.

It is a still further object of the invention to provide means wherebyshould any obstruction prevent movement of the rudder blades injury tothe blades will be avoided by preventing the further application ofpower thereto until so desired.

It is a still further object of the invention to provide gearing todecrease the speed of operation of the rudder bladesywhile increasingthe power communicated thereto.

Further objects of theinvention will hereinafter appear and 'bespecifically pointed out in the appended claims.

In the accompanying drawings, which are intended to illustrate apreferred embodiment of the invention but which are not regarded as inany way limiting the invention the scope of which is defined in theappended claims, the preferred embodiment of my invention is shown asapplied to controlling means in which the movement of the blades iseffected by the'displacement of a member on a threaded spindle, such asde scribed in U. S. Patent lid 13714192, but the particular arrangementof means effecting the movement of the blades forms no part of thisinvention which relates to power driven means for operating same.

As above stated the particular form of rudder to which this inventionrelates forms the subject matter of a U. S. patent and therefore onlysuflicie-nt description of the operation thereof will be here given toenable a clear understanding of the invention to be obtained.

Fig. 1 is a sideelevation of a complete power unit mounted on a commonbase plate adapted to be mounted adjacent the rudder.

Fig. 2' is a front elevation of he unit shown in Fig. 1, showing thesolenoid brake arrangement.

Fig. 3 shows a convenient arrangement or the control means in the wheelhouse, push buttons controlling the necessary switches being arranged ina box mounted on the binnacle.

Fig. at is a detail view of the limit switch arrangement of the unitshown in Fig. 1.

Fig. 5 is a plan view of the control engine and rudder gear showing therelation of the unit shown in Fig. l to the rudder control.

Fig. 6 is a diagran'nnatic representation of as much of the electricalcircuits of the power unit as is necessary in order to coinprehend themanner in which the ttunctioi'iing of the mechanism is controlled, thesetting ot' the switches being that for ahead maneuvering.

The rudder referred to and known in the isiarine neering art as theKitchen inaneuvering and reversing rudder consists c'ssentially of twoblades 1], 12 each substantially semicircular in vertical section andpivoted together vertically preferably no as'to surround the propeller.The blades are so shaped alongthe rear vertical edge that they may bebrought into contact throughout the length of said rear edge, theirinner :taces then being substantially at right angles and preventing thepassage of any water therebetween.

One of the blades or deflectors is operated by a "solid shattfld and theother by a hollow shaft 7 concentric with the solid shatt. By suita' lemechanism the deflectors or rudders are made to turn together in thesame direction or equally in opposite direct'ions.

To be as effective as possible the rudder should be placed in, or near,the propeller race. This ensures that the speed of the water passingover the rudder will be greater than the speed of the vessel through thewater by a varying value which may be much as 30 per cent; and that instarting the ship from rest there will be a flow of water over therudder, giving steering power etore the vessel has much weight on.- Thisis effected in the most efficient way possible, since not only are theblades in the propeller race but confine the race adjacent thepropeller.

Variation of speed.l or ordinary direct full speed ahead the rudder willbe opened until nearly parallel, beingslightly less at the after end.lihen the deflectors are partiall'y, closed, the speed otthe boat. willbe reduced to about one-half the full ahead speed, the ei'igines stillrunning at the same revolutions. When the rudders are closed stillfurther the boatwill remain stationary. ln this case the forward thruston the propeller is balanced by an equal astern thrust on the rudders.When the deflector's'are closed together, the reaction on the rudderscauses the vessel to go astern. This position gives the maximum asternspeed.

Sztcm iii.g.lhe vessel can be steered by carrying helm on the rudders,whether they be fully open, partially closed or quite closed. It hasbeen found that 25 degrees to 30 degrees of helm is quite sufiicient forall practical purposes, although with ordinary rudders as much 38degrees or even 4-0 degrees of helm is used. This limitation of helmangle tends to decrease of size in the steering gear. Under theseconditions the vessel can be mate to turn about on axis somewhere nearher middle length without moving ahead or astern. Similarly, helm can becarried with the rudders fully closed, when the vessel turns while goingastern.

in order to provide for the power control of the above describedmaneuvering gear I provide an electric motor 1 which, preterably throughreduction gearing, drives the threaded spindle 2, on which is mountedthe nut 3, adapted to be displaced by the rotation of said threadedspindle.

Pivoted at the centre of its length to this not is a yoke l, and links5, pivoted at one end to thecndsor the yoke l, are pivoted at theirother ends to the armti mounted on the shaft A attached to one deflectorblade 11, and arm 8 mounted on a sleeve 7 attached to the otherdeflector blade 12, by this construction it will be readily seen thatthe rotation of the motor in the desired direction during a. determinedperiod rotates the spindle 2 thereby displacing the nut 3, and, throughthe yoke i and links 6 and'l, opening or closing the blades 11, 12 thedesired amount.

it is desirable that means. should be provided to ensure that therequired setting of the blades is accurately attained when the motorcircuit is interrupted.

F or this reason automatic means are put in operation to cause veryrapid stoppage of the rotation of the motor shaft, and since the spindleis driven from the motor shaft at a considerable reduction in speed, astill more rapid stoppage of the said'spindle. This mechanism in theillustrated embodiment of my invention takes the form of a brake havingshoes mounted on pivoted arms 13 on opposite sides of a brake drum 11 i,and normally drawn together by a powerful spring 10, thereby preventingrotation of said drun'i. Immediately the motorcircuit is completed asolenoid is energizer and is arranged to draw down one end ot a lever l5which through suitable linkage forces apart the ends of the pivoted armsit? thus releasingthe brake drum on the motor circuit being interruptedthe solenoid is deenergized allowingthe spring 10 to again 1 V Kuy erake;

One convenient method of mounting the controls in the wheel house isshown in Fig. 3 from which it will be seen that three push buttonsmarked Ahead Astern and Reset are arranged in a i all control boxmounted on the binnacle.

This control is obviously extremely simple and can readily be operatedby the man at the wheel who is thus enabled to control the entiremaneuvering of the vessel, .a' very aluafule advantage especially invessels manned by small crews, such as tugs, barges or small yacht-s.

.t is desirable to provide means to ensure that no injury shall occur tothe rudder plates or straining of the actuating mechanism resultingthrough some obstruction preventing the movement Off the blades,

and to take care of this contingency an over-.

load switch is arranged to automatically break the electrical operatingcircuit when the resistance to movement of theblades becomes undesirablygreat.

In the power unit shown a switch marked Reset is provided on the controlboard by which the circuit can be reestablished after being sointerrupted, but this does not set the mechanism in movement untileither the ahead or astern button is depressed, thus by depressing theahead button the blades may be re-opened to release the obstruction andthe closing movement then ire-commenced by depressing'the asternbutton.- I I Means are preferably provided to prevent the blades'beingmoved beyond a certain maximum setting. In the construction shown in thedrawings this is provided for byarranging that the motor circuit isbroken when-the limiting positionis reached by adjustably mountedtripping members 17, 18 on a member 17 displaced along a threadedspindle rotated during the rotation of the motor 1. In the arrangementshown this spindle 20 is formed as an extension of a shaft 21 driven bythe motor through'a worm reduction gear. hen the contact carrier 1'? hasbeen displaced to the end of its travel one of the contacts 17, 18carried thereby acts tothrow a switch 22 which, as will be seen from.the circuit diagram acts to interrupt the circuit of the solenoid 23holding closed the line switches 21. The opening ot' lhese switchesstops the motor and automatically applies the brake. Obviously anyconvenient arrangeimant of limit switches or stops could be substitutedfor the particular arrangement just described which 1s given as anillustratire example and has been used with periectly satisfactoryresults in actual practice, and while I have shown. byway ofillustration a convenient arrangement of electrical control circuit itwill of course be understood thatmy invention is not in any way limitedto the-precise arrangement of said circuit as any suitable lay out ofthe necessary electrical apparatus may be utilined, such a system forinstance as that used in electric trains or cars.

The operation of the describet andillustrated embodiment of my inventionis as follows. j

It is presumed that a ship is pulling out of a dockby going astern andfor some reason, such as a craft passing across the stern, it is desiredto reduce lier speed, the push button marked Ahead is pressed and keptdepressed until the speed falls to that desired. In the ahead setting otthe switches a path is established for the current drawn from the mainline by the auxiliary line branching from the main line at D, thecurrent flowing through the contacts connected by the reset controlswitch in its normal or open position, through the contacts connected bythe ahead control switch in its operative or closed position, throughthe contacts connected by the astern control switch inits normal or openposition, through the energizing solenoid 25 for the main ahead controlswitch thereby closing that switch, andzjoining the return side of themain line circuit at the main line switch 24.

During the depressionot the ahead con-- trol switch it will be seen thatthe solenoid S holding oii tie electromagnetic brake is also energized.On releasing the ahead control switch, the circuit just described isinterrupted deenergizing the brake solenoid and causing the automaticapplication of the brake with the result'that the rudder plates are heldin a position at whichthey have arrived substantially at the instant ofinterruption f the powerjcircuit.

It is to be noted that the term ahead denotes that the rudder blades areopening into more andmore parallel relation to each other; to continueour illustration we will suppose that the ship having been brought fromabout 4 miles per'hour astern to one mile an hour, it is desired toagain increase her speed to full astern, the button marked Aster-n isdepressed and held depressed. In this astern setting of the switches apath is established for the current drawn from the mainline by theauxiliary circuitlju'anching therefrom at D, the current passingtln'oughthe terminals connected by the reset control switch in normal or openposition to the terminals connected by the astern control switch initsdepressed or closed position, the terminals connected by the aheadCOHblOlfiWltCll in its normal or open position, through the solenoid oithe main astern control switch 3%) thereby 'elrs-o close the switch cometogether until in the normal case they would come into contact, but wewill suppose a piece of timber jams between the closing edges andabruptly arrests their movement. The overload switch 27 is thrown, bythe heavy rush of current through its solenoid, and the auxiliary oicuitthrough the solenoid 23 holding shut the main line switch istie-energized, the switch leing thrown open by the tension spring 24,thereby practically instantly stopping the motor by the applicationot'the brake. The overload switch 27 immediately atter is brought by anysuitable means Such as a spring or the weight of its armature, intoposition to restore the circuit of the main line switch 2% but as thisswitch is held open by its spri 2% it is necessary to marked Reset toestablish the auxiliary circuit serving to energize the solenoid servingto close the main line switch and hold it closed against the tension ofthe spring 2%. In this se'ting it will be seen tl at an auxiliarycircuit is established branching from the main line at D, currentflowing from said main line through the terminals connected by the resetcontrol switch in its depressed or closed position through the solenoidholding closed the. main line switch against the null of its retractingc, l a

spring 2?, and tlirough the terminals connected by the overload switchin its normal or closed position to the return side of the circuit, themain line switch 24 being maintained closed on the release of theresetswitch by the feeding of line current drawn from the main line at Eand flowing through a local circuit completed by a secondary switch 28connected to the main line switch so as to be moved into closed positionby the closing of-the main line switch and through the solenoid of saidmain line switch. to the return side or" the circuit. The rudder platescan now be opened sutticiently to release the obstruction by depressingthe switch marked Ahead and then the aster-n button can be againdepressed, the blades moving together till their edges are in contactwhen, should the buttonbc still kept depressed, the astern limit switchis tl rown and the motor stopped, the ship then going full speed asternas long as is desired.

it is believed that the operation of the power control means has beenmade clear and that it will be seen that a simple and reliable? controlhas been provided capable of being operated by the steersma-n it desiredand therefore enabling all maneuvering of the ship to be eii'ected byone man and without varying the engine speed, these conditi being verydesirable in many cases. nile I have described a power control. unitwhich has been found in actual practics of great-value and to functionperfectly, I do not desire to limit myself to, the precise details ofconstruction shown, as various alternative ways of obtaining the tituresof the control of my invention can be readily conceived by those skilledin the art and I do not therefore desire to limit the scope of theinventio except as defined in the appended claims.

I claim 1. In ship or boat maneuvering gear of the kind described, anelectric motor, rudd er blades movable by said motor toward or from each0th r, means normally tending to cause interruption of the circuit ofsaid motor but adapted to be held out of normal position to enablemovement of the rudder blades'to be effected, means acting on therelease of said control means to immediately interrupt the circuit ofthe motor, a shaft rotated by said motor, reduction gear transmittingthe drive from said shaft to members actingto transmit the drive to therudder blades and brake means automatically applied on the interruptionof the notor ,circuit to arrest the movement of said shaft.

2'. In ship or boat maneuvering gear of the kind described, a sourcesupplying power, rudder blades movable toward or from each other, meansoperated by power from said source for moving said blades, controllingmeans whereby the time during which power is applied tothe rudder bladesis determined, and additional controlling means to cut off said powershouldvan obstruction prevent movement oitsa-id blades 3. In ship orboat maneuvering gear of the kind described, rudder blades movabletoward or from each other, an electric motor, means for controlling thecircuit of said motorand an overload switch acting to interrupt themotor circuit should the movement of said rudder blades be prevented,the circuit remaining open till again closed bysaid controlling means.

4. In ship or boat maneuvering gear of the kind described, rudder bladesmovable toward or from each other, an electric motor, a shaft rotated bysaid motor and driving a worm, a worm wheel meshing with said worm, ashaft rotated by said worm wheel,

and members moved along said shaft by the movement thereof and acting tointerrupt the circuit of said motor when the rudder blades have reachedtheir maximum settings in either direction.

5.'In ship or boat maneuvering gear ol' the kind. described, an electricmotor, and circuit control means for said motor adapted to be arrangedin a suitable position adja cent the navigator, said circuit controlmeans comprising a switch for running of the motor in one direction, asecond switch for causing running of the motor in the reverse direction,an overload switch, and a third switch. whereby the circuit may; bereset after interru ition thereoi' owing to any cause imposing anoverload on said circuit resulting in the opening of the overloadswitch.

6. In ship or boat maneuvering gear of the hind described, an electricmotor, a shaf rotated said motor and driving a worm, a worm wheelmeshing with said worm, a

brake drum mounted on said shaft, a brake shoe engaging with said drumand arranged to be applied automatically on the interruption of themotor circuit, a second shaft driven by a bevel pinion from said worm sitch means to automatically interrupt the motor circuit on the rudderblades reaching their limiting positions, switch means antomatically tointerrupt the motor circuit should the movement of the rudder blades beobstructed and electro-magnetically operated braking means automaticallyapplied by the interruption of the motor circuit to bring the mechanismto a stop.

8. In ship or boat maneuvering gear of the kind described, an electricmotor, switch means arranged to control the running thereof in eitherahead or astern direction, switch means to automatically interrupt themotor circuit on the rudder blades reaching their limiting positions,switch means automatically to interrupt the motor circuit should themovement of the rudder blades be obstructed, electro-magneticallyoperated braking means automatically applied by the interruption of themotor circuit to bring the mechanism to a stop, said braking meanscomprising a brake slice member, means tending to force said brakemember into engagement with a member driven by said motor and a solenoidnormally energized and acting to hold said braking memher out ofengagement with said driven member and switch means acting automaticallyto interrupt the energizing circuit of said solenoid when the desiredsetting of the rudder blades has been attained thus putting the brakeinto operation.

9. In ship or boat maneuvering gear of the kind described, an electricmotor, switch means arranged to normally break the motor circuit so thatsaid motor can be run in either direction for a period determined by thetime the requisite switch is held out of normal position, automaticallyoperated means for interrupting the motor circuit when continuedapplication of power to the blades might result in damage, an electromagnetic brake held out of engagement during the functioning of themechanism but automatically applied by the interruption of the motorcircuit to stop said mecha nism, said brake comprising a brake shoebearing on a brake surface formed on a part rotated during thefunctioning ofthe mechanism, said shoe being carried on an arm pivotedat one end to the mechanism mounting, a spring arranged to exert apressure on the other end of the arm tending to force said shoe intoengagement with said bearing surface, and a solenoid energized duringthe functioning of the mechanism and acting through a lever to hold saidbrake shoe out of engagement, the de-energization of the solenoidallowing the spring to force the brake shoe into engagement and bringthe mechanism to a stop in a very short time.

In testimony whereof Ihave affixed my signature.

ALEXANDER MoNAB.

